Buttonhole-sewing machine.



aiamm G. S. HILL.

BUTTONHOLE SEWING MACH NE.

APPLICATION FILED APR. 26, me.

PatentedJuly 3, 1917.

2 SHEETS-SHEET I.

mi mfw G. S. HILL.

BUTTONHOLE SEWING MACHINE,

APPLICATION FILED APR. 25, 1916.

Patented July 3, 1917.

2 SHEETS-SHEET 2- GEORGE S. HILL, OF STRAFFORD, NEW HAMPSHIRE, ASSIGNORT UNITED SHOE MlrhGHINEB-Y COMPANY, OF PATERSON, NEW JERSEY, ACORPORATION OF rsnY.

EUTTONHOLE-SEWING MACHINE.

Patented July a, we a.

Application filed April 26, 1916. Serial No. 93,608.

' To all whom it may concern:

Be it hown thatI, GEORGE S. HILL, a citizen of the United States,residing at Straf- I ford, in the county of Strafi'ord and State ofpertains to make and use the same.

The invention relates to buttonhole sewing machines, and moreparticularly to mechanism for operating the thread tension of suchmachines. 0

In sewing machines of this class, and particularly in machines which areprovided with devices for holding the end of the needle thread at thebeginning of the sewing, it is desirable, if not essentlal, that theapplication of the tension of the threadat the beginning of the seam bedelayed until after the completion of the first stitch, as otherwise theend of the thread is liable to be ulled from the thread holder duringthe st cycle of the stitching mechanism, and before its end is properlyanchored in the seam. It is accordingly the obyect of the presentinvention to provide novel and improved mechanism which will so controlthe application of the tension that it will be applied at asubstantially uniform time in the second cycle of the stitchingmechan1sm, irrespective of any variations in the rela tive speeds of thestitchlng and feed mechanisms incident to changes in the number ofstitches to be .made in the buttonholes.

To this end the invention comprises the features of construction andcombinations of parts hereinafter described and referred to in theclaims, the advanta es of which Wlll. be understood by those s illed nthe art from the followin detailed description of a mechanism embo yingthe preferred form of the invention.

In the drawings, Figure 1 1s a s1de elevation of a buttonhole makingmachine embodyin the invention in its preferred form;

Fig. 2 1s a partial plan View of the machine; a

operation of the machine shown and described in Patent No. 1,063,880,June 3, 1913, and provided with a thread cutting and holding device suchas shown and described. in Patent No. 1,094,896, April 28, 1914. In thismachine the stitching mechanism comprlses an upper reciprocating needle2 and supplemental under thread mechanism (not shown) driven through ashaft 4 which makes one revolution for each cycle of the stltchingmechanism. The feed mechanism through which the work clamp and stitchingmechanism are relatively moved'during the sewing to form over-seamstitches about the buttonhole includes a cam gear 6 which makes onerevolution during the making of a buttonhole. The feed mechanism isdriven during the sewing from the stitching mechanism through gearingindicated at 8 which connects the shaft 4: with the gear 6, and which isso constructed that it may be readily changed to vary the speed of thecam gear with relation to the stitching mechanism, in accordance withthe number of stitches which are to be made in sewing about thebuttonhole. The machine is provided with a thread cutting and holdingdevice indicated at 10, which is operated at the completion of thesewing to cut and hold the upper needle thread, and which retains theend of the thread until the initial stitches have been formed at thebeginning of the next succeeding sewing operation, the thread holder andcutter being operated by cams on the feed cam gear 6, as fully describedin Patent No. 1,094,896. The upper needle thread, on its way from thethread supply to the needle, passes through a tension device comprisingthe lower fixed disk 12 and the upper spring-pressed movable disk 14.The tension 'dev1ce is controlled to apply or release the tensionthrough a tension releasing rod 16, the lower end of which rides on acam 18 secured to the upper face of the cam gear 6, and the upper end ofwhich carries a laterally projecting arm 20. The rear end of the arm 20supports a pin 22 which extends downward from a tension. As thus fardescribed, the machine is substantially the same in construction andmode of operation as the machine shown and described in the two patentsabove referred to.

In embodying the present invention in the above machine, it is preferredto retain the tension releasmg cam and rod 16, and to provide means forcontrolling the application of the tension at the beginning of thesewing from the sewing mechanism, so that the tension will be applied ata uniform time in the stitch forming cycle, irrespective of variationsin the extent of the movement imparted to the feed mechanism for eachstitch forming cycle. In its preferred form this means consists oflatching means which retains the tension in position of release, in.case the movement imparted to the feed mechanism during the firststitch forming cycle is sufficient to carry the tension release cam 18from beneath the rod 16, and which is tripped by the stitching mechanismto allow the tension to be applied at the proper time in the secondstitch forming cycle. As shown, the latching means comprises a latchlever 26 provided with a vertical arm arranged to underlie the arm 20 ofthe tension release rod when the rod is in tension releasing position,and also provided with a horizontal arm arranged to be engaged by a camor tappet carried by the shaft 4. The latch lever is forced yieldinglytoward latching position by a spring 28. It is preferred to so arrangethe horizontal arm of the latch lever that it will ride on the crank arm30 through which the under thread mechanism is operated, the crank armin such case acting as the cam or tappet for timing the application ofthe tension. It is to be understood, however, that the lever may beotherwise arranged, and may be tripped by any suitable cam or tappetsecured to or carried by the shaft and arranged or adjusted to trip thelatchand apply the tension at the desired time in the stitch formingcycle.

With the construction shown, the tension release rod 16 will be raisedat the end of the sewing by the cam 18 to release the tension, and thelatch lever 26 will immediately swing into position to support the rodin tension releasing position, the shaft 4 being stopped at thecompletion of the sewing, in the position indicated in the drawings. Atthe beginning of the next succeeding sewing operation the lever 26 willbe swung about its pivot by the crank arm 30 during the first downwardstroke of the needle 2, but at this time the cam 18 will still underliethe end of the rod 16, and will retain the rod in tension releasingposition; The latch lever will be immediately returned to activeposition beneath the arm 20 of end of the cam 18 passes fromunder theend of the rod, the latch will retain the rod in tension releasingposition until the latch is tripped to release the rod by the engagementof the crank arm 30 with the latch lever during'the second stroke of theneedle. The application of the tension at the beginning of the sewingwill therefore be accurately timed to take place at the proper time inthe second stitch forming cycle, irrespective of the number of stitchesto be made in the buttonhole, and of the rate of movement of the feedmechanism during each stitch forming cycle.

While it is preferred to employ the specific construction andarrangement of parts shown and described, in embodying the invention inthe machine of the patents above referred to, it will be understood thatthis construction and arrangement is not essential to the broaderfeatures of the invention, and may be varied or modified as founddesirable or best suited to the construction and arran ement of theparts of the machine in which the invention is to be embodied.

.one form of mechanism in which it may be embodied, what is claimedis 1. A buttonhole sewing machine, having, in combination, stitchingmechanism, feed mechanism, driving connections between the stltchlngmechanism and feed mechanism, means for applying tension to the threadat the beginning of the sewing controlled from the feed mechanism, andmeans for controlling the application of the tension from the sewingmechanism.

2. A. buttonhole sewing machine, having, in combination, stitchingmechanism, a thread holder, a tension device, feed mechanism, drivingconnections between the stitching mechanism and feed mechanism havingprovision for varying the speed of the feed mechanism with relation tothe stitching mechanism, means for controlling the tension device fromthe feed mechanism, and means operated from the sewing mechanism forpreventing premature application of the tension at the beginning of thesew- 1n I 3. A buttonhole sewing machine, having, in combination,stitching mechanism comprising a reciprocating needle, feed mechanismfor relatively feeding the work and stitching mechanism to sew about abuttonduring thesecond cycle 0 the sewing mechanism.

4:. A buttonhole sewing machine, having,

the tension releasingrod, and in case the in combination, stitchingmechanismcomnasnem prising a reciprocating needle, a tension device forthe needle thread, means for preventing the application of the tensionduring the first stroke of the needle at the beginning of the sewing,and means operated from the sewing mechanism for applying the tensionduring the second cycle of the stitching mechanism 5. A bnttonholesewing machine, having, in combination, stitching mechanism, feedmechanism, a tension device, means for .releasing the tension at thecompletion of the sewing, means for latching the tension in position ofrelease, and means operated by the stitching mechanism for tripping thelatching means to apply the tension;

6. A buttonhole sewing machine, having, in combination, stitchingmechanism, a tension device, feed mechanism provided with a tensionrelease cam, means. for latching the tension in position of release, andmeans operated by the stitching mechanism for tripping the latchingmeans to apply the tension.

7. A hnttonhole sewing machine, having,

-in combination, stitching mechanism comprising an upper reciprocatingneedle, feed mechanism for-relatively feeding the work and stitchingmechanism to sew about a louttonhole, a thread holder for holding thethread at the beginning of the sewing, a tension device, means forcontrolling the application of the tension from the feed mechanism, andmeans for timing the application of the tension from the stitchingmecha- 8. A buttonhole sewing machine, having, in combination, stitchingmechanism comp a reciprocating needle, a tension device for the needlethread, means for releasing the tension at the completion of the sewing,means for latching the tension in position of release, means fortripping the latching means duringeach stitch forming cycle, and meansfor preventing the application of the tension when the latching means istripped during the first stitch forming cycle.

GEORGE S. HILL.

